Efficient Synthesis of Soft Nanomaterials Through Transition Metal-Catalyzed Polymerization

技术综述：本研究的目标是开发高效催化合成具有非常规结构和性能的软纳米材料。纳米材料在催化、传感器、生物成像、药物输送和电子学等方面的各种纳米技术应用方面得到了积极的研究。在众多体系中，基于树枝状聚合物的纳米材料因其在溶液中呈球形，分子尺寸正好在纳米范围内而备受关注。尽管许多合成方法都很精致，但通过分步合成制备树枝状纳米材料的难度和常规树枝状大分子的极限尺寸限制要求人们寻找更有效的方法来构建树枝状纳米结构。这项计划详细说明了应用和结合各种催化聚合方法来高效合成软纳米材料的计划。在第一部分中，将独特的链步聚合与原子转移自由基聚合(ATRP)和开环歧化聚合(ROMP)相结合，设计出非常规的线状-树枝状嵌段共聚物。在第二部分中，提出了在多位链状催化剂上同时生长树枝状纳米粒子和树枝状大单体聚合的方法作为构建分子纳米对象的有效方法。合成的新型软纳米材料的物理性能将在PI的实验室中进行仔细的研究，并与美国和其他国家的其他材料科学家合作。非技术摘要：这项拟议的研究旨在开发催化聚合方法，以有效地制备软功能纳米材料，这些材料对各种纳米技术应用非常重要，包括催化、传感器、生物成像、药物输送和电子学。该合成将通过高效的过渡金属催化的烯烃聚合来实现，这些烯烃在石油工业中很容易获得。从简单的烯烃单体开发高价值纳米材料的成功将对聚烯烃工业产生重大影响。此外，制备复杂和多功能的软纳米材料的有效方法可能会加速许多纳米技术的发展。拟议的多学科研究活动将为学生提供许多领域的优秀培训，包括有机合成、有机金属、聚合物合成和性质研究，以及纳米科学。这将为培养研究生和本科生提供很好的机会，特别是对少数民族和女性学生。

TECHNICAL SUMMARY:The objective of the proposed study is to develop highly efficient catalytic synthesis of soft nano-materials having unconventional structures and properties. Nanomaterials are actively investigated for various nanotechnology applications including catalysis, sensors, bio-imaging, drug delivery, and electronics. Among other systems, nanomaterials based on dendritic polymers have received much attention because they have globular shape in solution with molecular dimensions right in the nanometer range. Despite the elegance of many syntheses, the difficulty of preparing dendritic nanomaterials through step-wise synthesis and the limit of ultimate size for regular dendrimers warrant the search of more efficient methodologies for constructing dendritic nanostructures. This proposal details the plan to apply and combine various catalytic polymerization methods to efficiently synthesize soft nanomaterials. In the first part, the unique chain walking polymerization will be combined with atom transfer radical polymerization (ATRP) and ring-opening metathesis polymerization (ROMP) for designing unconventional linear-dendritic block copolymers. In the second part, simultaneous growth of dendritic nanoparticles on multi-sited chain walking catalysts and polymerization of dendronized macromonomer approach are proposed as efficient methods for constructing molecular nano-objects. The physical properties of the synthesized novel soft nanomaterials will be carefully investigated both in the PI's laboratory and through collaboration with other materials scientists in the United States and other countries.NON-TECHNICAL SUMMARY:This proposed research is aimed at developing catalytic polymerization methods for efficient preparation of soft functional nanomaterials that are important for various nanotechnology applications including catalysis, sensors, bio-imaging, drug delivery, and electronics. The synthesis will be achieved by efficient transition metal catalyzed polymerization of olefins that are easily accessible from petroleum industry. Successful development of high value nanomaterials from simple olefinic monomers will have significant impact on polyolefin industry. In addition, efficient methods for preparing complex and multifunctional soft nanomaterials may potentially accelerate many nanotechnological developments. The proposed multi-disciplinary research activity will provide excellent training for students in many areas including organic synthesis, organometallic, polymer synthesis and property studies, and nanoscience. This will provide great opportunities to train graduate and undergraduate students, especially for minority and women students.